Asphalt batcher for pugmill



April 2, 1957 w. H. WYLIE 2,787,450

ASPHALT BATCHER FOR PUGMILL Filed June 1, 1954 2 Sheets-Sheet l INVENTOR ATTORNEYS April 2, 1 957 w. H. WYLlE ASPHALT BATCHER FOR PUGMILL 2 Sheets-Sheet 2 Filed June 1, 1954 I III! INVENTOR ATTORNEYS ASPHALT BATCHER FOR PUGMILL William H. Wylie, OklahomaCity, Okla.

Application June 1, '1954,'Serial No. 433,663

2 Claims. ((1 259-164) This invention rel'atesto asphalt mixing machines, and more particularly to an improved means for discharging measured quantities of liquid asphalt into the pugmill of an asphalt mixing machine.

in an asphalt mixing machine, apparatus is provided for effecting the drying of gravel or crushed stone, for heating-asphalt and delivering the asphalt and stone to a pugmill. It is an object of this invention to provide an improved asphalt delivery system and apparatus whereby a measured quantity of asphalt in liquid condition is delivered to the pugmill.

Another object of this invention is to provide in an asphalt mixing machine, apparatus for delivering hot asphalt which includes a continuously operating pump which will maintain the delivery chamber full of liquid asphalt.

In one form of the invention the hot asphalt is discharged from the measuring or delivery chamber by gravity.

In a modified form of this invention the delivery chamber is closed, and when hot asphalt is pumped into the chamber, air in the chamber is placed under pressure; and when the air reaches a predetermined maximum a relief valve will open so that the continuously operating pump will, upon opening of the relief valve, return the asphalt to the reservoir.

A further object of this invention is to provide a pugmill charging system wherein the hot asphalt is continuously circulated so that the system will not clog, and will be ready for operation at all times.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a perspective view, partly broken away, of a combined preheating and metering device for delivering asphalt to a pugmill.

Figure 2 is a longitudinal section of the structure shown in Figure 1.

Figure 3 is a fragmentary sectional view taken on the line 3-3 of Figure 2.

Figure 4 is a fragmentary sectional view taken on the line 44 of Figure 2.

Figure 5 is a fragmentary longitudinal section of a modified form of this invention.

Figure 6 is a fragmentary sectional view taken on the line 6--6 of Figure 1.

Referring to the drawings, and first to Figures 1 to 4 and 6, the numeral 10 designates generally a tank within which asphalt is adapted to be positioned, and the asphalt in tank 10 is adapted to be heated to a liquid state by a suitable heating means engaging therebeneath.

A pugmill or mixer 11 is disposed at one end of the tank 10 and embodies a substantially U-shaped member having mixer blades 13 secured on a shaft 14. The t from tank 10 is adapted to be discharged into the ited rates Patent '0 r"ice 2,787,450 Patented Apr. 2, 1 957 pugmill '11 in measured amounts as will be hereinafter described.

In order to provide a means whereby a measured quantity of liquid asphalt may be discharged into the pugmill 11, I have provided a delivery compartment generally indicated at 15, which is fixed within the tank 10 and adjacent the top thereof.

The delivery compartment or member 15 is formed of opposite side Walls 16, a bottom wall 17 which inclines downwardly and outwardly towards the end wall 18 of tank 10. The delivery compartment or member 15 also includes an inner end wall 19 which is fixed in any suitable manner to the top wall 20 of the tank 10. The delivery member 15 also includes an outer end wall 21 which is fixed relative to the end Wall 18.

Preferably the side walls 16 have their upper edges 22 positioned downwardly from the top wall 20, and at least one of the side walls 16 is formed with an overflow cut out 23 so that the asphalt in delivery member 15 may overflow into the main tank 10.

The amount of asphalt in delivery member 15 is determined by means of a float 24 carried by a rock lever 25 and a pointer or gauge member 26 is fixed relative to the lever 25 and swings overa graduated dial 27 secured to the upper side of the top wall 20. Lever 25 projects through an opening 28 which is formed in the top wall 20.

The asphalt in tank 10 is continuously circulated by means of a pump 29 which has the intake or suction side thereof connected to an intake pipe 30 extending downwardly to the lower portion of the tank 10. The pressure side of the pump 29 is connected by means of a pipe 31 to one side 32 of a three-way valve 33.

A second side 34 of the three-way valve 33 is connected through the wall 18 to the lower portion of delivery member 15.

The third side 35 of the valve 33 is connected by a pipe connection 36 to a perforated spray member 37 which is disposed in the upper portion of the pugmill 11 as shown in Figure 1.

The pump 29 includes a conventional by-pass element 38 whereby when valve 33 has the plug 39 thereof turned to provide for draining of the asphalt from delivery member 15 thereby cutting oii pressure pipe 31, the pressure of the asphalt in pump 29 will open the conventional by-pass valve so that pump 29 can operate continuously.

The lower end of intake pipe 30 as shown in Figure 4, has a strainer 41) secured thereto for straining the liquid asphalt which is drawn into the suction pipe 30.

Referring now to Figure 5, there is disclosed a modified form of this invention embodying a tank 41 similar to tank 10 which has secured therein a delivery member 42. The delivery member 42 is entirely closed with respect to the inside of the tank 10 and is connected by means of a pipe 43 to the pressure side of the circulating pump, and pipe 43 is connected to one side 44 of three-way valve 45 which is similar to valve 33.

An air pressure gauge 46 is connected with the top wall 47 of tank 41 and communicates with the upper portion of the inner tank of delivery member 42.

A safety valve 48 is connected with the inner lower portion of the delivery member 42 so that when a predetermined pressure of air is generated in the upper portion of delivery member 42, the asphalt will be discharged from delivery member 42 into tank 41. In other respects the structure shown in Figure 5 is similar to that shown in Figures 1 to 4 and 6, inclusive.

In the use and operation of this device, the tank 19 is filled with a predetermined quantity of asphalt which is maintained in the liquid state by heating means of con ventional construction.

Pump 29 is continuously operated from a driving member 49 so that delivery member 15 will be maintained in a filled condition at all times until the valve 33 has the plug 39 thereof turned, as shown in Figure 6, for dis charging the liquid asphalt from delivery member 15 into the pugmill 11. The quantity of asphalt discharged from delivery member 15 is gauged or determined by the pointer 26. 7

Where the structure shown in Figure is used, tank 42, which may be initially filled with air, is substantially filled with asphalt when valve member 45 is turned and the air in the space 50 is compressed and the pressure of the air communicated to the pressure gauge 46.

If desired, the tank 41 may have a petcock 51 secured to the top wall 52 thereof in communication with delivery tank 42 so that the amount of asphalt in delivery tank 42 may be closely regulated. When valve 45 is turned to deliver the asphalt in delivery member 42 into the pugmill the air pressure in space 50 will force the asphalt out of the delivery member 42 into the pugmill.

With a construction as hereinbefore described, the pump which is used for delivering the hot asphalt to the pugmill may be continuously operated by reason of the circulating system hereinbefore described which will provide for free circulation of the hot asphalt.

What is claimed is:

1. In combination, a pugrnill, a hot asphalt tank, a closed air filled delivery chamber in said tank, a pump, means connecting the suction side of said pump to said tank, means connecting the pressure side of said pump to said chamber-to fill said chamber with hot asphalt under a head of compressed air, a three-way valve interposed in said second named connecting means, a delivery connection between said valve and said pugmill to discharge said asphalt under said compressed air head, and a relief valve carried by said chamber projecting into said tank.

2. In combination, a pugmill, a hot asphalt tank, a substantially rectangular delivery chamber in said tank, said tank including top and bottom walls and a plurality of side walls, a pump, means connecting the suction side of said pump with the interior of said tank adjacent the lower end thereof, a conduit having one of its ends connected with the pressure side of said pump, a valve in said conduit for selectively directing hot asphalt from said conduit to either of the said pugmill and the said delivery chamber, said delivery chamber being connected to said top wall and one of said side walls.

References Cited in the file of this paten UNITED STATES PATENTS 808,599 Crichfield Dec. 26, 1905 1,600,948 Poore Sept. 21, 1926 1,829,066 Shelton Oct. 25, 1931 1,987,243 Madsen Jan. 8, 1935 2,280,518 Ball Apr. 21, 1942 

